In manufacturing of hollow bodies, e.g. bottles, boxes and other objects of thermoplastic material it is known to provide wordings by embossing the surface. For this purpose the blow mould must have a corresponding engraving. However, a disadvantage is that such a wording cannot easily be read, because there are no light or color contrasts. To avoid this disadvantage hollow bodies are very often printed after manufacturing. However, in addition to printing, this requires a special operation because of the properties of the material. It is, e.g. necessary, to subject the containers to a flame prior to printing, so that they accept the printing color. After printing the containers must run through drying tunnels. Accordingly, printing is relatively expensive and has further the disadvantage that heating may cause shrinking of the containers. In addition much manufacturing space is required for these operations.
It is also known to provide containers with labels after the blow operation or the filling operation. In this case very often stringent requirements are made on the exact form of the labeling surface on the container. These requirements may already increase the manufacturing cost of the container. A disadvantage is also the time lost by possible malfunction of the labeling machine. Very often labeling is made on a filling line, so that a malfunction on labeling may stop the whole production line.
It is already known to put a label or a plastic foil with pictures to the container within the blow mould. However, this requires expensive moulds and is only possible within relatively narrow limits, i.e. only on certain labeling surfaces, because a window must be provided on the mould to insert the label. In addition the space for the necessary mechanism must be present. A disadvantage is further, that the attaching of the label increases the cooling time for the blow cycle. The cooling ducts cannot be located optimally, because of the windows for feeding labels. Accordingly the cooling cycle becomes longer. This increases production cost. Also the higher tool cost for a mould with labeling windows increases production cost. An additional advantage is that economic manufacturing with multiple forms is not possible.